Vulnerability

    CPU (?)

Affected

    Sparc 5/170

Description

    Frank van der Linden found following.  Compile the following:

        main(){while(1);}

        with `gcc -O' on a SPARC.  You get, roughly:

        L1:
                 b,a L1
                 retl

    `ret' and `nop' also appear to  `work' (i.e. cause the hang).   It
    appears to be the branch instruction alone that's responsible  for
    the hang.  A non-annulled branch does not have the same effect.

    This  bug  seems  to  be  reproducable  only  on  170  MHz   SS5s.
    Specifically, the CPU that hangs is identified as a MB86907  (made
    by Fujitsu), running at 170 MHz.   It hangs when running the  same
    code under either Solaris 2.5.1  or NetBSD 1.3_ALPHA, so this  bug
    may not be OS-related.

    CPU wedges completely; all response from I/O peripherals is  dead,
    including L1-A on the keyboard and break on a serial console.

Solution

    Reboot.  It is not clear yet what is it, but it seems like nothing
    OS related.